Deduplicate GitHub Actions Usage

[MikeMcQuaid]

Provide a detailed description of the proposed feature

Homebrew/homebrew-core and Homebrew/linuxbrew-core (and, to a much lesser extent, Homebrew/brew) have a huge amount of duplication and copy-paste between actions that differ in very small ways. These should be deduplicated and move of their logic moved to Homebrew/actions.

Composite actions (https://docs.github.com/en/actions/creating-actions/creating-a-composite-run-steps-action) may be a simple way to simplify some of these workflow files and keep them in sync.

What is the motivation for the feature?

Reducing complexity due to repeated duplication in GitHub Actions workflow files.

How will the feature be relevant to at least 90% of Homebrew users?

More reliable CI.

What alternatives to the feature have been considered?

Not doing this.

[GauthamGoli]

I've spent some time on this, posting the findings here.

Composite actions don't support setting conditionals, continue-on-error, timeout-minutes, "uses", and secrets on individual steps within a composite action right now. (Reference: actions/runner#646)

The actions which we want to be deduplicated use one of the above unsupported statements/features. We'll have to park this idea until then.

As of now, we can only use composite actions to replace a bunch of run statements, which is a very narrow use case.

[MikeMcQuaid]

Thanks @GauthamGoli! Looks like composite actions are a non-starter for now, indeed. Do you have any other ideas on how to deduplicate? Perhaps we could have e.g. a single workflow that takes more inputs?

[GauthamGoli]

@MikeMcQuaid yeah, using a single workflow seems promising. I will open a PR if it works!

[xakep8]

Can we do something like process scheduling, like in apt?

[MikeMcQuaid]

@xakep8 I'm not sure I understand the question, please elaborate!

[mohzulfikar]

Hi there, I want to ask about this issue. From what I understand, homebrew has a custom action repository in here. So, if I want to create new composite action I should place the composite action in there and then use it on other repository. Is that the correct flow?

[dawidd6]

Yes

[mohzulfikar]

Thank you

[MikeMcQuaid]

I think this is as done as it needs to be.